Not exactly. Still favouring Rainbow Tree. Won't be the first time a quiz setter has got the wrong number of letters. I'm still searching for alternatives so if you're subscribed to this post - watch this space as they say.
I think that I may have found the answer for this one and excuse the pun, but I think you could be 'barking up the wrong tree' looking for an answer with the word 'tree' - try a different four letter word instead. Don't ask me for the answer as I know that most people just like clues (myself included) but I hope that this helps